Improvement in axle-tree foe



' G. P. KIMBALLQ Axle.

No. 69,819. Patented Oct. 15, 1867.

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GEORGE i. KIMBALL, OF SAN FRANCISCO, GALlFO-RNIA.

Letters Patent No. 69,819, dated October 15, 1861.

IMPROVEMENT IN AXLE-TREE FORWAGONS.

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TO WHOM IT MAY CONCERN:

Be it known that I, GEORGE P. KIMBALL, of San Francisco, in the county of San Francisco, and State of California, have invented certain new and useful Improvements in Axle-Trees;- and I hereby declare the following-to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, in which-- Figure lit; a perspective view of an axle-tree constructed in accordance with my invention.

Figure 2 is an elevation ,of the same.

Figure 3 is a top view of the wooden axle-bed; and

Figure 4 is a like view of the steel mile-tree.

A represents the steel contract the axle-tree. B Bare the arms upon which the wheels are held. O is the bed or wooden part of the tree, which is flat at its base, and gradually decreases in width towards the top.

The axle-tree proper A is a fiat metal plate, the centre part of which is steel, while the arms 13 are either" steel or iron, as preferred. This plate is very thin compared with ordinary axle-trees, increasing, however, in thickness as it approaches the ends or arms 13. Its width, on the contrary, lessens as it approaches the arms, being greatest at the centre, asshown in figs. 1 and 4. The wooden portion or axle-bed G is applied to the steel tree in the usual manner, the two being held together by belts or other suitable means, as shown in the drawings, therebeingon top of the wooden bed a centre plate of metal, through which the bolts pass which hold this portion ofthe tree to the bed. In consequence of the great width of the steel tree at the centre the bolt-holes do not weaken the tree, as in the case with those made of iron. This extra width prevents the lateral bending, or, as it is termed, taking the set out of the axle tree. Thegreat strength of the steel compared with iron admits of the bar A being made very thin, so as to have less than half the weight of an ordinary axle-tree, At the same time the depth of the wooden-part O is proportionately increased, the weight of the combined wooden'and steel tree, however, being not more thanhalf the weight of the cbmmon axle-tree and bed, while, a't the same time, it possesses muc more strength and durability, and is indued with a degree of elasticity which can never be attained in ordinary trees. It is notvso liable .to-spring out or under as other trees, and will, under all circumstances, stand a heavier blow. The wagon body is supported upon the axle-bed O in any ordinary or suitable manner. To avoid danger of the wagon becoming disconnected from the trees, as sometimes :happens through the breaking of bolts, I employ a safety-hook, which, although shown in the drawings, is nothere described, as I contemplate making it the subject of a separate application for Letters Patent.

From the-:above described construction of my improved axle-tree, it-wi-lI be seen that the-steel-centre tree forms, in fact, a spring-plate, which tapers in width, and increases in thickness, as it approaches what may be called its Hearing points, 2'. 0., the arms 13 upon which the wheelsturn. Bycombiningwith this spring-platethe wooden bed 0', an axle-tree is obtained which, while possessing powers of resistance greatly superior to ordinary axle-trees, has an elasticity which other trees do not-possess, and are not intended to possess. The great tensile strength and flexibility of the steel 'pl'ate especially adapt it for the purpose for which it is used, whilethe wooden bed imparts to the whole the necessary firmness. This elasticity of the steel plate gives to the tree a. certain springines's and liveliness of action which will carry the wagon in which such trees are used over all obstacles, such as are usually met with on roads, with scarcely a jar.

Having now described my invention, and the manner in which the same is or may be carried into effect, what I claim, and desire to secure by Letters Patent, is

The combination, with a'superposed wooden axle-bed, of the steel plate or spring axle-tree A, constructed and arranged for operation substantially as herein shown and for the purposes set forth.

GEORGE P. KIMBALL.

Witnesses:

JAMES SMILEY, HENRY Harem. 

